Consumers eat differently at home.

Think fancy cheeses. Some dairy cows make excellent milk for cheese. The input into this market is raw milk. When that market disappears due to restaurants closing, it's a serious problem.

While overall consumption remains the same (or similar, people need to eat) there's different supply chains involved in commercial and consumer consumption.

Say you've got a bottling plant that sells exclusively to commercial suppliers. The cost to retool to produce consumer packaged products is non-zero. Your shipping is all geared to commercial suppliers as well.

If you decide to reorient to produce consumer packaged goods this takes some amount of time. The farmers that supply you have a batch of milk right now they're storing and a batch coming up next week. If you can't take delivery, you don't have infinite cold storage for milk after all, they need to dump their milk because they've for another batch on the way they'll need to store. You may also have milk stored in your refrigerated tanks waiting for you to be able to reorient for consumer packaging. If your tanks are full you're not going to get new supplies.

There's a lot of supply chains that have a lot of momentum and they've been optimized for throughput because that's what gives everyone involved the best margins. When demand drops it takes time and money to slow down or adjust the supply chain because of the momentum. Things like milk can be more difficult because they need not just storage but refrigerated storage and shipping.

You might have milk and I might want milk but we're far apart and if you can't get it to me (safely) I'm not going to buy it. That's not to say it's good farmers are dumping otherwise good food. Dealing with perishable things is not the same as dry goods. You can't just add more trucks or warehouses and problem solved.

Restaurants can't put leftovers in the fridge, so there's a huge amount of waste in the restaurant system.

Where did you get this idea? It depends on the item, but most things do get rolled over from one day to the next.

Not necessarily for the same products - people cooking at home aren't deep-frying everything.

"What I cook for myself at home" and "what I order in restaurants" are two pretty disjoint sets.

I'm not even sure the total number of calories will come out 1:1; are people eating less because they're not commuting or working? Eating better because they are cooking? Eating worse because they are depressed? I can't even guess.

Not necessarily, people don't cook the same things they purchase at restaurants. Additionally, a fair number of people don't seem to be competent at cooking much past a scrambled egg, so a lot of people choose packaged/prepared foods versus raw ingredients.

According to the article about 1/3 of food is thrown away. I would guess that consumers are throwing away less food and producers who typically sell to restaurants are throwing away more.

Sure, but the type of food people consume at home typically differs greatly from the food they eat out.

Keep in mind that in this situation, the goal is to ensure that already-grown food isn’t wasted and is able to be processed, not necessarily meeting the perfect market demand that you’d see in normal economic conditions.

Packaging and labeling are different for bulk commercial and small-package grocery-store logistics.